Informatica Software Developer Engineer interview questions

1. Design data structures for top N trending items for retail shop. Items keep on coming online and trends keep on chaning (idea : use heap data structure... max heap will give you top trending item) 2. BST tree related code ..fairly easy. Like convert BST to greater sum tree. 3. some matrix puzzle and I could not code but explain the logic as he was more interested in logic only. 4. puzzle on weight.. easy one 5. B tree code was given and I had to tell what this code doing/..fairly easy with recursion understanding.